[beta] fix failing const validation

[RalfJung]

This is the beta branch fix for #71353, by reverting #70566.

r? @oli-obk
Not sure if there is any extra process for the beta part. This is not a backport; we intend to "properly" fix this on master but for beta a revert is faster and less risky.

[rust-highfive]

⚠️ Warning ⚠️

• Pull requests are usually filed against the master branch for this repo, but this one is against beta. Please double check that you specified the right target!

[Mark-Simulacrum]

I think given the timeline I'm fine with this going into beta without full compiler team approval (since it could've landed in master just days ago).

cc @pnkfelix @rust-lang/wg-prioritization -- does that seem reasonable? We can also treat this as a beta-nominated PR at tomorrow's meeting, I guess.

[RalfJung]

Some git checkout failed on the GHA builder, no idea what's up with that

fatal: Not a valid commit name b2e36e6c2d229126b59e892c9147fbb68115d292
thread 'main' panicked at 'command did not execute successfully: "git" "merge-base" "a7d891e31a85269d0d0164258f2b6b6670129763" "b2e36e6c2d229126b59e892c9147fbb68115d292"
expected success, got: exit code: 128', src/build_helper/lib.rs:131:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/test/mir-opt --pass=build --target=armv5te-unknown-linux-gnueabi

[JohnTitor]

Some git checkout failed on the GHA builder, no idea what's up with that

I guess because rollup landed during running CI. That points to b2e36e6.

[Mark-Simulacrum]

I believe that's a spurious failure -- ls-remote returns the current master commit which may not be checked out locally if master was pushed after CI on the PR started. We only started seeing this now because previously (and still) pipelines didn't run on beta PRs and beta auto branch builds always happened in isolation (not in parallel with master merges).

I've retriggered the builds.

[RalfJung]

This time all three failed...

[pnkfelix]

@Mark-Simulacrum (at this point we're just going to treat this as if it were nominated for beta backport, even though I understand it is not a backport)

[oli-obk]

We discussed this at the compiler meeting yesteday and decided that we'd prefer a master PR and backport that to beta in the regular way. If you worry that the backport will be too big, maybe just do the revert on master, backport that and fix the root issue again

[RalfJung]

I thought @pnkfelix was going to forward-port this same change to master, and we could still use this PR here for beta?

[oli-obk]

oh, I guess I misremembered, sorry

[Mark-Simulacrum]

@bors r+ rollup=never

Received approval from @pnkfelix over Discord and generally it seems we're good to go here.

[bors]

📌 Commit 622c84a has been approved by Mark-Simulacrum

[Dylan-DPC-zz]

@bors p=1

[bors]

⌛ Testing commit 622c84a with merge b1162ed...

[bors]

☀️ Test successful - checks-azure
Approved by: Mark-Simulacrum
Pushing b1162ed to beta...